1. 1. Shimizu, T, and Kondo, H. (1973) : Japan. J. Med. Sci. Biol., 26, 269-271.
2. 2. Rymkiewicz, D., Sawicki, J, and Brühl, A. (1979) : Arch. Immun. Therap. Exptl., 27, 709-714.
3. 3. Kozaki, S., Sakaguchi, S. and Sakaguchi, G. (1974) : Infect. Immun., 10, 750-756.
4. 4. Kozaki, S., Miyazaki, S. and Sakaguchi, G. (1977) : Infect. Immun., 18, 761-766.
5. 5. Miyazaki, S., Kozaki, S., Sakaguchi, S. and Sakaguchi, G. (1976) : Infect. Immun., 13, 987-989.